A particularly cost effective and practical cam selector mechanism for effecting selection from a relatively small number of different pattern cams in a stack is disclosed in the U.S. patents of Urciola et al. U.S. Pat. No. 3,699,910, Oct. 24, 1972 and Graham et al. U.S. Pat. No. 3,753,411, Aug. 21, 1973. The present invention provides for an improvement in the above referenced pattern cam selector mechanisms which may be effected without materially increasing the complexity of construction but which significantly decreases the force required of a sewing machine operator to effect pattern cam selection. The above mentioned U.S. patents represent the closest prior art known to the inventors which is pertinent to the present invention.